2.6.27-stable review patch. If anyone has any objections, please let us know.

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From: Hugh Dickins <hugh.dickins@tiscali.co.uk>

commit 1ac0cb5d0e22d5e483f56b2bc12172dec1cf7536 upstream.

do_anonymous_page() has been wrong to dirty the pte regardless.If it's not going to mark the pte writable, then it won't helpto mark it dirty here, and clogs up memory with pages which willneed swap instead of being thrown away. Especially wrong if noovercommit is chosen, and this vma is not yet VM_ACCOUNTed -we could exceed the limit and OOM despite no overcommit.